title: Performance of various commercial assays for the detection of Toscana virus antibodies.
abstract: BACKGROUND
  Sandfly fever virus (SFV) serotypes sandfly fever Naples virus, sandfly fever Sicilian virus, and sandfly fever Cyprus virus cause febrile diseases, whereas Toscana virus (TOSV) is responsible for aseptic meningoencephalitis. Diagnosis and surveillance of TOSV depend heavily on virus serology, and various commercial assays utilizing various antigen sources and formats have been available. The aim of this study was to perform comparative evaluation of commercially available serological assays for anti-TOSV immunoglobulins.
  
  
  METHODS
  A collection of 120 sera from healthy blood donors from an endemic region, previously identified to be reactive for antibodies against various SFV serotypes by indirect immunofluorescence test (IIFT), was reevaluated for IgG/IgM via IIFT, enzyme-linked immunosorbent assay, and an immunoblot assay manufactured by Euroimmun, Diesse, and Mikrogen, respectively. Virus neutralization test (VNT) was performed for 99 sera using standard TOSV, sandfly fever Sicilian virus, and sandfly fever Naples virus strains.
  
  
  RESULTS
  A total of 89 samples (74.2%) were reactive for TOSV IgG in at least one of the commercial assays, and 31 samples (31.3%) were reactive in VNT for various SFV serotypes. Average percentage agreements among commercial assays and between VNT and the commercial assays were noted as 57.8% and 62.6%, respectively. No significant correlation between assay results and VNT titers was observed. SFV IgM antibodies were detected in a total of eight samples (6.7%) via IIFT, which were nonreactive in enzyme-linked immunosorbent assay and VNT.
  
  
  CONCLUSIONS
  Commercial diagnostic immunoassays displayed slight to fair agreement for TOSV IgG as assessed via kappa and percentage agreement values. The results could only be confirmed via virus neutralization in a portion of the samples, and overall agreement between the commercial assays and VNT was slight. Commercial assays such as immunoblot can be used in addition to VNT for confirmation of TOSV exposure.
authors.affiliation: Department of Medical Microbiology, Virology Unit, Faculty of Medicine, Hacettepe University, Ankara, Turkey. ekoray@hacettepe.edu.tr
authors.forename: Koray
authors.initials: K
authors.lastname: Ergünay
authors.forename: Nadine
authors.initials: N
authors.lastname: Litzba
authors.forename: Modou Moustapha
authors.initials: MM
authors.lastname: Lo
authors.forename: Sibel
authors.initials: S
authors.lastname: Aydoğan
authors.forename: Mehmet B
authors.initials: MB
authors.lastname: Saygan
authors.forename: Dürdal
authors.initials: D
authors.lastname: Us
authors.forename: Manfred
authors.initials: M
authors.lastname: Weidmann
authors.forename: Matthias
authors.initials: M
authors.lastname: Niedrig
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D006801:Humans; D015151:Immunoblotting / Q000379:methods*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D009500:Neutralization Tests / Q000379:methods*; D015203:Reproducibility of Results; D029301:Sandfly fever Naples virus / Q000276:immunology*; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M